Network virtualization is the process of combining hardware and software network resources into a single, software-based administrative entity as a virtualized network. Software defined networking is an example of network virtualization in which hardware network resources are decoupled from software network resources in order to simplify network management, and allow software developers to treat network hardware resources in the same manner that they treat storage and computer resources. Software defined networking allows network intelligence to be centralized in software-based controllers, thereby allowing network hardware devices to function as simple packet forwarders that can be programmed by way of an open interface.
Networks may be susceptible to covert attacks through side channel attack techniques. Side channel attacks are attacks on networks based on information gained from the physical implementation of the network.